The abbreviation DVB-T stands for the term Digital Video Broadcasting – Terrestrial. The first successful attempt of DVB-T usage was carried out in 1997 in Great Britain and since then the technology has won the considerable popularity around the world (Radio Electronics, 2009). The work of the DVB-T is based on the use of the so-called COFDM (also called OFDM), which stands for the Coded Orthogonal Frequency Division Multiplex (or simply Orthogonal Frequency Division Multiplex) and is the “form of transmission that uses a large number of close spaced carriers that are modulated with low rate data” (Radio Electronics, 2009). The usual television broadcasting technologies resort to the use of one certain type of signals because traditionally the different signals interfere with each other if they are used simultaneously. However, the DVB-T uses the orthogonal positioning of the various signals and this fact makes their interference impossible (Radio Electronics, 2009).
Moreover, there are two modes in which the DVB-T can be used; they include 2K- and 8K-modes (DVB, 2009). The modulation schemes used include QPSK, 16QAM, and 64QAM. Thus, DVB-T transmits several blocks of data at a symbol rate, and the use of the COFDM and its tool called Guard Interval allows avoiding the interference of the blocks with each other and enables the DVB-T receiver to distinguish between multiple signal bocks (DVB, 2009). Finally, DVB-T demands a DVB-T receiver and a DVB-T transmitter. They both resort to the use the COFDM modulation, split the data, decode them, transmit, and encode as for the demands of the receiver (DVB, 2009).
Typology of DVB-T
Needless to say, the recent rather fast development of the DVB technology has contributed greatly to the diversification of the latter. Thus, except DVB-T, there are such types of DVB as DVB-S (Digital Video Broadcasting – Satellite), DVB-S2, DVB-T2, DVB-C (Digital Video Broadcasting – Cable), DVB-H (Digital Video Broadcasting – Handheld), and DVB-SH (DVB, 2009). All the technology types in this list are based on the DVB standards and their differences lay in the mode they use for operation. In other words, DVB technologies mentioned differ according to the instrument of broadcasting, whether it is a satellite, a cable network, or a mobile PC (DVB, 2009).
In more detail, DVB-S and its modified version DVB-S2 are based on the satellite-facilitated data transmission. It is powered by the MCPS and SCPC modes and is accepted as one of the best forward error coding and modulation systems. DVB-S2 is characterized by the use of updated technology including the HDTV and H.264 (MPEG – 4 AVC) solutions and specialized video codecs (DVB, 2009). DVB-C is the technology of digital television transmission through cable and with the help of QAM modulation system launched through the channel coding technique (Radio Electronics, 2009). DVB-H, as a mobile digital television technology, is carried out through the help of the mobile DVB receiver and is possible in the VHF-III, UHF-IV/V, and L bands only (Radio Electronics, 2009). Finally, DVB-SH is the hybrid of the three other DVB technologies, i. e. DVB-T, DVB-S, and DVB-H. Thus, DVB-SH facilitates the transmission of digital television signals to the handheld receivers through either satellite or terrestrial DBV technologies (Radio Electronics, 2009).
DVB-T Use in Australia
Needless to say, the DVB-T technology, as the widely used and rather progressive in the modern world, is considerably popular in the countries all over the globe. Europe, Asia, and America use this technology to facilitate the better quality of digital television and fight the interference of various signals broadcasted at the same frequencies (Radio Electronics, 2009). Australia is also one of the countries to use the DVB-T technology. If the first testing broadcast of the DVB-T took place in Great Britain in 1997, Australia adopted this technique for its television broadcasting systems already in 1998 (Cordis, 1998).
The reason why the Australian Digital Terrestrial Television Broadcasting (DTTB) Selection Panel adopted the use of the DVB-T was that the latter is rather useful in solving Australian broadcasting issues, among which the so called “digital cliff-edge” is the most burning one (Cordis, 1998). The essence of this issue is in the fact that the specific Australian geographic location and natural and climatic conditions create the state when people inhabiting some regions receive better quality of television than others living in other areas. The latter are the inhabitants of the above mentioned “digital cliff-edge”, i. e. the area where television broadcast signals are split and distorted (Digital TV, 2001). DVB-T is the technology allowing Australian TV to avoid this issue and provide the viewers with the better quality of broadcasting. Therefore, Australia has been an active DVB-T user for over 10 years.
List of Technologies Required for DVB-T
Every technological solution demands some means that enable its operation. The technologies that make DVB-T possible include:
- MPEG – 2 TS (Transport Stream)
- STB (Set Top Boxes)
- HDTV and SDTV
- MPEG – 4 (Radio Electronics, 2009)
Cordis. “Digital Television in Australia – Success for DVB-T.” 1998. Infowin. Web.
Digital TV. “So What’s This DVB-T Then?” 2001. Digital Television in Australia. Web.
DVB. “Digital Video Broadcasting.” 2009. DVB Official Web Site. Web.
Radio Electronics. “What is DVB-T?” 2009. Radio Electronics.com.